AGITATOR

n. one who agitates, one who causes unrest, propagandist, inciter, troublemaker

Agitator is a term for a person that actively supports some ideology or movement with speeches and especially actions.
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Noun
1. one who agitates; a political troublemaker
(synonym) fomenter
(hypernym) troublemaker, trouble maker, troubler, mischief-maker, bad hat
(derivation) agitate, foment, stir up

n. agitator, one who agitates, one who causes unrest, propagandist, inciter, troublemaker

n. agitator, inciter; activist